Process for preparing clear bright oleaginous aluminum dispersions

ABSTRACT

A process for preparing clear bright oleaginous aluminum dispersions comprising admixing an oil soluble dispersing agent, an oleaginous carrier and a volatile solvent with a dispersible alumina, heating and recovering a clear bright oleaginous aluminum dispersion.

United States Patent [191 [111 3,867,296 Hunt Feb. 18, 1975 PROCESS FOR PREPARING CLEAR [56] References Cited BRIGHT OLEAGINOUS ALUMINUM UN D STATES PATENTS DISPERSIONS 2,469,041 5/1949 Jones 252/35 [75] Inventor; Mack W, Hunt, P n a City, Okla 3,018,172 l/l962 Tillman 44/5l 3,250,710 5/1966 Hunt 252/33 [73] Assignee: Continental Oll Company, Ponca City, Okla. Primary Examiner-Delbert E. Gantz [22] Flled: June 1973 Assistant ExaminerAndrew H. Metz [21] Appl. No.2 373,564 Attorney, Agent, or Firm-F. Lindsey Scott Related US. Application Data [63] Continuation-impart of Ser. No, 230,065, Feb. 28,

1972. abandoned.

[57] ABSTRACT Forelgn Apphcatlon Prmmy Data A process for preparing clear bright oleaginous alumi- Oct. 26,1972 Canada ..l55062 num dispersions Comprising admixing an Oi] Soluble dispersing agent, an oleaginous carrier and a volatile [52] US. Cl 25 /3 2 8' solvent with a dispersible alumina, heating and recov- 252/ 52/33. 252/3 2, 2 2/308, 252/309 ering a clear bright oleaginous aluminum dispersion. [51] Int. Cl Cl0m l/40 [58] Field of Search 252/19, 26, 33, 33.4, 37,

13 Claims, No Drawings 1 PROCESS FOR PREPARING CLEAR BRIGHT OLEAGINOUS ALUMINUM DISPERSIONS This application is a continuation-in-part of U.S. Ser. No. 230,065 now abandoned of the same title filed Feb. 28, 1972.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the dispersion of metals in oleaginous materials. This invention further relates to a process for dispersing aluminum in oleaginous materials. This invention further relates to a process for dispersing aluminum in oleaginous materials by the use of sulfonic acids and carboxylic acids as dispersing agents.

2.Brief Description of the Prior Art It has been known heretofore that dispersions of aluminum in oleaginous materials can be prepared by a variety of methods. Several such methods are shown in the following references which were considered in the prior art search conducted on the concept of the present invention.

U.S. Pat. No. 2,585,520 issued Feb. 12, 1952, to Van Ess et al.; U.S. Pat. No. 2,676,925 issued Apr. 27, 1954 to Lindstrom et al.; U.S. Pat. No. 3,018,172 issued Jan. 23, 1962 to Tillman; U.S. Pat. No. 3,061,419 issued Oct. 30, 1962 to Sias et al.; U.S. Pat. No. 3,149,074 issued Sept. 15, 1964 to Tillman; Australian Patent No. 200,149 issued to Garner et al. and published May, 1955; and Belgium Patent No. 498,777 issued to Fagerholt et al. and published Februrary 15, 1951. The references considered most relevant are U.S. Pat. No. 3,018,172 and Australian Patent No. 200,149.

U.S. Pat. No. 3,018,172 to Tillman shows a process for preparing dispersions of aluminum in mineral oils and the like by a process wherein aluminum alkoxide is dispersed in an alkanol, mixed with a mineral oil containing an oil soluble detergent material such as sulfonate materials and thereafter hydrolyzed to produce a dispersion of alumina. The process requires a hydrolysis step in an oil media which necessitates mixing an aqueous portion with an oily portion and, of course, subsequent separation of the aqueous and oily portions.

Australian Patent 200,149 discloses a process for dispersing alumina in oleaginous materials containing sulfonic acids by a mechanical milling technique; however, the dispersions obtained are not shown to be clear high quality dispersions but rather are primarily intended for use as fuel oil additives and the like.

Accordingly, much time and effort has been devoted to a search for a better method for preparing dispersions of aluminum in oleaginous materials whereby such products may be produced by simpler methods and of an improved quality.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a simplified method for preparing an aluminum dispersion in oleaginous materials.

It is a further objective of the present invention to provide a method whereby clear bright aluminum dispersions in oleaginuos materials may be prepared.

SUMMARY OF THE INVENTION It has now been found that the objectives of the present invention are achieved by admixing an oil soluble dispersing agent selected from the group consisting of oil soluble sulfonic acids in which the hydrocarbon portion has a molecular weight from about 300 to about 1000 and carboxylic acids containing at least about 8 carbon atoms, an oleaginous carrier and a volatile solvent with alumina prepared by the water hydrolysis of aluminum alkoxides and having the following properties:

crystal structure alpha alumina monohydrate crystal structure after calcining to 900F. gamma alumina (3) Ultimate crystal size (x-ray diffraction) 020 reflection 30-70A ()21 reflection 60-1 10A (4) pore volume 0.35-0.65 cc/g (5) loose bulk density 35-70 lh/ft (6) particle size (sieve) 45 micron 207i 45 micron (7) A1 0 content 65-85 wt. 71 (8) Loss on ignition 15-35 wt. 71 (9) Surface Area -350 in lg,

to form a mixture of uniform consistency and thereafter heating said mixture to substantially remove all of said volatile solvent and recovering clear bright aluminum containing dispersions.

PREFERRED EMBODIMENTS Aluminum dispersions in oleaginous materials such as those produced by the process of the present invention are useful as fuel oil additives, jet fuel additives, motor fuel additives, lubricant additives and the like. The dispersions of the present invention are particularly useful since such dispersions contain substantial amounts of aluminum in a clear bright dispersion suitable for use in high quality motor oils and the like.

According to the process of the present invention, aluminum containing dispersions are prepared by admixing an oil soluble dispersing agent, an oleaginous carrier, and a volatile solvent with a dispersible alumina and heating the mixture to remove said volatile solvent and recover the aluminum containing dispersion.

Suitable oil-soluble dispersing agents include the oilsoluble sulfonic acids and carboxylic acids. The term oil-soluble sulfonic acids, as used herein, refers to those materials wherein the hydrocarbon portion of the molecule has a molecular weight in the range of about 300 to about 1,000. Preferably, this molecular weight is in the range of about 370 to about 700. These oilsoluble sulfonic acids can be either synthetic sulfonic acids or the so-called mahogany or natural sulfonic acids. The term mahogany sulfonic acid is believed to be well understood, since it is amply described in the literature. The term synthetic sulfonic acids" refers to those materials which are prepared by sulfonation of hydrocarbon feedstocks which are prepared synthetically. The synthetic sulfonic acids can be derived from either alkyl or alkaryl hydrocarbons. In addition, they can be derived from the hydrocarbons having cycloalkyl (i.e. naphthenic) groups in the side chains attached to the benzene ring. The alkyl groups in the alkaryl hydrocarbons can be straight or branched chain. The alkaryl radical can be derived from benzene, toluene, ethyl benzene, xylene isomers, or naphthalene.

An example of a hydrocarbon feedstock which, has been particularly useful in preparing synthetic sulfonic acids is a material known as postdodecylbenzene. Postdodecylbenzene is a bottoms product of the manufacture of dodecylbenzene. The alkyl groups of postdodecylbenzene are branched chain. Postdodecylbenzene consists of monoalkylbenzenes and dialkylbenzenes in the approximate mole ratio of 2:3 and has typical properties as follows:

Specific gravity at 38C. 0.8649 Average molecular weight 385 Percent sulfonatable 88 A.S.T.M. D-l58 Engler:

I.B.P., F. 647 5 F. 682 50 F. 715 90 F. 760

95 r F. '175 F.B.P. F. 779 Refractive Index at 23C. 1,4900 Viscosity at:

l0C., centistokes 2,800 C,, centistokes 280 40C., centistokes 78 80C., centistokes l8 Aniline point, C. 69 Pour Point, F.

An example of another hydrocarbon feedstock which is particularly useful in preparing synthetic sulfonic acids is a material referred to as dimer alkylate. Dimer alkylate has a long, branched-chain alkyl group. Briefly described, dimer alkylate is prepared by the following steps:

dimerization of a suitable feedstock, such as cat poly gasoline, and

2. alkylation of an aromatic hydrocarbon with the dimer formed in step (1).

Preferably, the dimerization step uses a Friedel-Crafts alkylation sludge as the catalyst. This process and the resulting product are described in U.S. Pat. No. 3,410,925, issued Nov. 12, 1968 to Eby et al. In order to make my disclosure even more complete, U.S. Pat. No. 3,410,925 is made a part of this disclosure.

The oil-soluble sulfonic acids are preferred for use in my process. a

In addition to the sulfonic acids derived from the foregoing-described hydrocarbon feedstock, examples of. other suitable sulfonic acids include the following: monoand poly-wax-substituted naphthalene sulfonic acid, dinonyl naphthalene sulfonic acid, diphenyl ether sulfonic acid, naphthalene disulfide sulfonic acid, dicetyl thianthrene sulfonic acid, dilauryl beta-naphthol sulfonic acid, dicapry] nitronaphthalene sulfonic acid, unsaturated paraffin wax sulfonic acid, hydroxy substituted paraffin wax sulfonic acid, tetraamylene sulfonic acid, monoand poly-chloro-substituted paraffin wax sulfonic acid, nitrosoparaffin wax sulfonic acid; cycloaliphatic sulfonic acid such as lauryl-cyclohexyl sulfonic acid, monoand poly-wax-substituted cyclohexyl sulfonic acid, and the like.

Suitable carboxylic acids which can be used in preparing the aluminum dispersions include napthenic acids, such as the substituted cyclopentane monocarboxylic acids, the substituted cyclohexane monocarboxylic acids and the substituted cyclohexane monocarboxylic acids and the substituted aliphatic polycyclic monocarboxylic acids containing at least 15 carbon atoms. Specific examples include cetyl cyclohexane carboxylic acids, dioctyl cyelopentane carboxylic acids, dilauryl decahydronaphthalene and stearyloctahydro indene carboxylic acids and the like and oilsoluble salts thereof. Suitable oil-soluble fatty acids are those containing at'least about 8 carbon atoms. For producing the dispersions of this invention in liquid form, I prefer fatty acids which are liquids at ambient temperatures down to about 15"Cv Specific examples include Z-ethy] hexanoic acid, pelargonic acid, oleic acid palmitoleic acid, linoleic acid and riconoleic acid. Naturally occurring mixtures of predominantly unsaturated fatty acids, such as tall oil fatty acids, are particularly suitable. Examples of commercially available tall oil fatty acids include the Crofatols", available from Crosby Chemical Company and the Acintols". available from Arizona Chemical Company.

A wide variety of oleaginous carriers are suitable in the process of my invention. The principal requisites in the oleaginous carrier are that it acts as a solvent for the dispersing agent used, has a viscosity from about 60 to about 500 SUS at F and has a boiling point of at least C. at normal atmospheric pressure. Suitable oleaginous carriers include materials boiling in the lubricating oil range and lower boiling refinery hydrocarbon streams, such as Stoddard solvent and diesel fuels. Examples of nonvolatile diluents boiling in the lubricating oil range which can be used include mineral lubricating oils obtained by any of the conventional refining procedures; synthetic lubrication oils, such as polymers of propylene, polyoxyalkylenes, polyoxypropylene, dicarboxylic acid esters, and esters of phosphorus; synthetic hydrocarbon lubricating oils. such as dialkylbenzenes, diphenylalkanes, alkylated tetrahydronaphthalenes, and mixtures of these materials; vegetable oils, such as corn oil, cotton seed oil, and castor oil; and animal oils, such as lard oil and sperm oil. Of the nonvolatile diluents described hereinbefore, the mineral lubricating oils and the synthetic lubricating oils are considered more suitable, with the mineral lubricating oils being preferred.

Volatile solvent as used herein refers to hydrocarbon solvents having a boiling point at normal atmospheric pressure of less than about 300F. Some specific examples of such solvents are: petroleum naptha, hexane, heptane, octane, benzene, toluene, glycol ethers, monohydric alcohols containing from about 1 to about 6 carbon atoms and the like. Very desirable solvents are hexane, heptane, benzene, butanol and the monomethyl ether of ethylene glycol.

The dispersible alumina useful in the process of the (1) crystal structure alpha alumina monohydrate (2) crystal structure after calcining to 900F gamma alumina (3) Ultimate crystal size (x-ray diffraction) 020 reflection 30-70A 02l reflection 60-! 10A (4) Pore volume 0.35-0.65 cc/g (5) loose bulk density 35-70 lb/ft (6) particle size (sieve) 45 micron 20% 45 micron 80% -Continued It has been found that uniquely desirable aluminum dispersions are produced by the process of the present invention when such alumina is used. Tests with other alumina products has failed to yield comparable products as will be shown in the examples hereinafter.

As will be apparent to those skilled in the art the process of the present invention can be carried out using only the alumina and oil soluble dispersing agent, however, it is expected that great difficulty will be obtained in admixing the components and the like. Similarly the volatile solvent may be omitted, however, it has been found that the addition of such solvents is beneficial in achieving intimate mixing of the components, reduction of viscosity during processing and the like. While such modifications are possible, it is pointed out that the preferred practice of the present invention is accomplished by the admixture of the oil soluble dispersing agent, the oleaginous carrier and volatile solvent prior to the addition of the alumina. Following the addition of the alumina further mixing of the components is desirable prior to heating the mixture to remove the solvent by distillation. Optionally, an inert stripping gas may be used in the latter stages of the heating operation to improve the effectiveness of the distillation in removing the last traces of the organic solvent.

The addition of from about 1 to about 20 weight percent water, based on the alumina added is beneficial. The process is equally effective without the addition of water but the water apparently aids in obtaining desirable aluminum dispersion and is readily removed with the volatile solvent as overhead during the heating step. Very desirable results have been obtained when about weight percent water was used. The process as noted above is equally effective with no water present and the use of water will be found most desirable in those embodiments wherein the increased ease in dispersing the alumina offsets the added load on heating and solvent recovery equipment.

When proper amounts of alumina are added, the product may be recovered directly from the distillation vessel after removal of the volatile solvent. In many applications it may be desirable to add an excess of alumina to achieve a maximum dispersion of aluminum in the end product. in such instances, it would be desirable to use a filtration step to obtain the clear bright product. The aluminum dispersions so produced contain up to about weight percent aluminum. While we do notwish to be bound by any particular theory, it is believed that portions of the aluminum are present as the aluminum sulfonate and the remaining portions are present as dispersions of alumina.

As noted herebefore the aluminum dispersions so produced contain up to about 20 weight percent aluminum. Those dispersions containing more than about 6 weight percent aluminum are preferred since less of the dispersion is required to incorporate a given amount of aluminum into blends to which the dispersion is added. In many applications those dispersions containing more than 10 weight percent aluminum are preferred. A preferred range is from 8 to about 20 weight percent aluminum.

Numerous modifications and variations of the above process are possible within the scope of the present invention and may appear obvious or desirable to those skilled in the art based upon a review of the preceding description of the preferred embodiments and the following examples and claims EXAMPLE 11 (a) specific gravity 6.287 lb/gal (b) sulfonic acid content 24.6 wt. (c) oil content SUS paraffinic) 9.1 wt. (d) water content 1.0 wt. (e) hexane content 65.3 wt. (f) average sulfonic acid 455 molecular weight The sulfonic acid was derived from a mixture of synthetic alkylbenzenes consisting of 35 weight percent monoalkylbenzene derived from a straight chain mono olefin and having an average molecular weight of about 420, 15 weight percent mono-alkylbenzene derived from a branched chain mono olefin and having an average molecular weight of about 379 and 50 weight percent dialkylbenzene derived from straight chain mono olefins and having an average molecular weight of about 370. An additional 250 gallons of hexane was added. The mixer was then turned on and 46 gallons of water was added followed by the addition of 3900 lbs of DISPAL alumina with continued mixing for about 30 minutes. The mixture was then heated to reflux and maintained at reflux for about 2.75 hours. 404 gallons ofa 300 SUS napthenic oil was then added and the solvents, i.e. hexane and water were removed as overhead by heating to 300F. Carbon dioxide stripping gas was introduced at cubic feet per minute during the latter stages of the heating step. The product remaining in the vessel weighed 9250 lbs and was a bright, clear, liquid dispersion containing 29 wt aluminum sulfonate, 38 weight percent naphthenic oil and 33 weight per- Cent A1203.

EXAMPLE 11 A one liter vessel was charged with 116.7 grams of sulfonic acid dissolved in 400 grams of hexane. The acid was derived in the same manner as that used in Example I. 37.9 grams of 80 SUS neutral oil commonly described as 80 pale oil was added to the mixture and thereafter 12.5 grams of DISPAL alumina was added. The mixture was stirred well for about 30 minutes at room temperature and then heated to about 150C for about 20 minutes. Nitrogen gas was admitted as a strip ping gas in the latter part of the heating step. The product remaining in the bottom of the vessel weighed 94.8 grams and had the following properties: 30 weight percent aluminum sulfonate, 4.8 weight percent aluminum, 0.32 percent BS&W and electron micrograph tests disclosed that the average particle size was less than 0.1 micron with the majority of particles being 0.01 micron or less.

EXAMPLE 111 Similar tests were run using other alumina products. The test results and alumina properties are shown in Table 1.

Table 1 Sample Number Alumina Properties l 2 3 4 5 6 Pore Volume (cc/g) 0.55 L20 0.53 1.90 0.87 0.7l Surface Area 200 300 274 350 N8 250 (mlg) Loose bulk density (lb/ft") 55 20 28 ll 24 31 M 0, (wt. 75 72 70 79 85 75 i Aluminum Dispersion Properties BS&W 0.2 22 8 100 l 24 Appearance Bright and Cloudy lis! @229! Very ls v.t Clear Milky Alumina is generally used to refer to air apparently dry solid or powder which usually contains some free water. water of hydration and the like as well as M Sample No. l was DlSPAL alumina. Sample No. 2 was an alumina marketed by Kaiser Chemical Co., P. O. Box 1031, Baton Rouge, La., under the trademark KCSA and has the properties shown. Sample No. 3 was alumina marketed by E. l. Du Pont de Nemours & Co. Inc., Wilmington 98. Del. under the trademark BAYMAL" and has the properties shown. Sample 4 was alumina prepared by the water hydrolysis of alumina alkoxides and thereafter contacted with methyl alcohol and dried. The product alumina had the properties shown above. Sample was prepared by the water hydrolysis of alumina alkoxides followed by purification and aging with heat prior to drying. The properties were as shown in Column 5. Sample 6 was a mixture of 75% DISPAL alumina and 25% BAYMAL alumina. A slurry of the mixture was spray dried to produce an alumina product having the properties shown above.

It is obvious from the Table the only alumina tested which produces a bright clear dispersion wherein the alumina is fully dispersed is the test wherein DISPAL alumina was used.

Having thus described the invention, I claim:

1. A process for preparing clear, bright aluminumcontaining dispersions containing at least 6 weight percent aluminum, said process comprising:

a. admixing an oil soluble dispersing agent, selected from the group consisting of oil soluble sulfonic acids in which the hydrocarbon portion has a molecular weight between about 350 and 1000 and hydrocarbyl carboxylic acids containing at least 8 carbon atoms, an oleaginous carrier selected from the group consisting of mineral lubricating oils, synthetic lubricating oils, vegetable oils and animal oils and a volatile hydrocarbon solvent having a boiling point at atmospheric pressure below about 300F. with alumina prepared by the water hydrolysis of aluminum alkoxides and having the following properties:

Crystal structure alpha alumina monohydrate Crystal structure after calcining to 900F gamma alumina (3) Ultimate crystal size (x-ray diffraction) 020 reflection 30-70 A 02] rcllcction 60-1 [0 A (4) Pore volume 0.35-0.65 ec/g (5) Loose bulk density 3570 lh/tt (6) Particle size (sieve) 45 micron 20% 45 micron 80% (7) A1 0 content 65-85 wt. (8) Loss on lgnition -35 wt. 70 (9) Surface Area 150-350 m /g to form a mixture of uniform consistency;

b. heating said mixture to remove substantially all of said volatile hydrocarbon solvent; and c. recovering said clear bright aluminum-containing dispersion.

2. The process of claim 1 wherein from about 1 to about 20 weight percent water, based on the alumina added is included in the mixture.

3. The process of claim 1 wherein said hydrocarbon portion of the sulfonic acid has an average molecular weight between about 370 and 700.

4. The process of claim 1 wherein said carboxylic acid is selected from the group consisting of naphthenic acids, hydrocarbyl substituted cyclohexane monocarboxylic acids, hydrocarbyl substituted polycyclic hydrocarbyl monocarboxylic acids containing at least 15 carbon atoms and naturally occurring mixtures of predominantly unsaturated fatty acids.

5. The process of claim 1 wherein said dispersions contain from 8 to about 20 weight percent aluminum.

6. The process of claim 1 wherein said volatile solvent is selected from the group consisting of petroleum naptha, hexane, heptane, octane, benzene, toluene, glycol ethers and monohydric alcohols containing from about 1 to about 6 carbon atoms.

7. The process of claim 5 wherein said volatile solvent is selected from the group consisting of hexane, heptane, benzene, butanol and the monomethyl ethers of ethylene glycol.

8. The process of claim 1 wherein said oleaginous carrier is selected from mineral lubricating oils, and synthetic lubricating oils.

9. The process of claim 1 wherein stripping gas is introduced during the latter portion of the heating step to further remove said volatile solvent.

10. The process of claim 1 wherein said oil soluble dispersing agent is an oil soluble sulfonic acid having an average molecular weight of about 420, said volatile solvent is hexane, said oleaginous carrier is pale oil, said heating is conducted at C for about 20 minutes and nitrogen is introduced as a stripping gas during the heating step.

ll. The process of claim l0 wherein water is added to the mixture in an amount equal to about 10 weight percent of the alumina added.

12. Clear bright aluminum-containing dispersions containing at least about 6 weight percent aluminum dispersed in an oil-soluble dispersing agent selected from the group consisting of oil-soluble sulfonic acids carboxylic acids containing at least 8 carbon atoms,-

and an oleaginous carrier selected from the group con- 13. The dispersion of claim 12 wherein said aluminum is present in a form selected from salts of said sulfonic acids, salts of said hydrocarbyl carboxylic acids and alpha alumina monohydrate and in an amount sisting of mineral lubricating oils, synthetic lubricating 5 equal to 8 tgalqout @Qweightpercent of the dispersion.

oils, vegetable oils and animal oils, prepared by the process of claim 1. 

1. A PROCESS FOR PREPARING CLEAR, BRIGHT ALUMINUMCONTAINING DISPERSIONS CONTAINING AT LEAST 6 WEIGHT PERCENT ALUMINUM, SAID PROCESS COMPRISING: A. ADMIXING AN OIL SOLUBLE DISPERSING AGENT SELECTED FROM THE GROUP CONSISTING OF OIL SOLUBLE SULFONIC ACIDS IN WHICH THE HYDROCARBON PORTION HAS A MOLECULAR WEIGHT BETWEEN ABOUT 350 AND 100 AND HYDROCARBYL CARBOXYLIC ACIDS CONTAINING AT LEAST 8 CARBON ATOMS, AN OLEAGINOUS CARRIER SELECTED FROM THE GROUP CONSISTING OF MINERAL LUBRICATING OILS, SYNTHETIC LUBRICATING OILS, VEGETABLE OILS AND ANIMAL OILS AND A VOLATILE HYDROCARBON SOLVENT HAVING A BOILING POINT AT ATMOSPHERIC PRESSURE BELOW ABOUT 300*F. WITH ALUMINA PREPARED BY THE WATER HYDROLYSIS OF ALUMINUM ALKOXIDES AND HAVING THE FOLLOWING PROPERTIES: (1) CRYSTAL STRUCTURE - ALPHA ALUMINA MONOHYDRATE (2) CRYSTAL STRUCTURE AFTER CALCINING TO 900*F - GAMMA ALUMINA (3) ULTIMATE CRYSTAL SIZE (X-RAY DIFFRACTION) 020 REFLECTION 30-70 A 021 REFLECTION 60-110 A (4) PORE VOLUME 0.35-0.65 CC/G (5) LOOSE BULK DENSITY 35-70 LB/FT (6) PARTICLE SIZE (SIEVE) 45 MICRON : 20% 45 MICRON - 80% (7) AL2O3 CONTENT 65 - 85 WT. % (8) LOSS ON IGNITION 15 - 35 WT. % (9) SURFACE AREA 150 - 350 M2/G TO FORM A MIXTURE OF UNIFORM CONSISTENCY; B. HEATING SAID MIXTURE TO REMOVE SUBSTANTIALLY ALL OF SAID VOLATILE HYDROCARBON SOLVENT; AND C. RECOVERING SAID CLEAR BRIGHT ALUMINUM-CONTAINING DISPERSION.
 2. The process of claim 1 wherein from about 1 to about 20 weight percent water, based on the alumina added is included in the mixture.
 3. The process of claim 1 wherein said hydrocarbon portion of the sulfonic acid has an average molecular weight between about 370 and
 700. 4. The process of claim 1 wherein said carboxylic acid is selected from the group consisting of naphthenic acids, hydrocarbyl substituted cyclohexane monocarboxylic acids, hydrocarbyl substituted polycyclic hydrocarbyl monocarboxylic acids containing at least 15 carbon atoms and naturally occurring mixtures of predominantly unsaturated fatty acids.
 5. The process of claim 1 wherein said dispersions contain from 8 to about 20 weight percent aluminum.
 6. The process of claim 1 wherein said volatile solvent is selected from the group consisting of petroleum naptha, hexane, heptane, octane, benzene, toluene, glycol ethers and monohydric alcohols containing from about 1 to about 6 carbon atoms.
 7. The process of claim 5 wherein said volatile solvent is selected from the group consisting of hexane, heptane, benzene, butanol and the monomethyl ethers of ethylene glycol.
 8. The process of claim 1 wherein said oleaginous carrier is selected from mineral lubricating oils, and synthetic lubricating oils.
 9. The process of claim 1 wherein stripping gas is introduced during the latter portion of the heating step to further remove said volatile solvent.
 10. The process of claim 1 wherein said oil soluble dispersing agent is an oil soluble sulfonic acid having an average molecular weight of about 420, said volatile solvent is hexane, said oleaginous carrier is 80 pale oil, said heating is conducted at 150*C for about 20 minutes and nitrogen is introduced as a stripping gas during the heating step.
 11. The process of claim 10 wherein water is added to the mixture in an amount equal to about 10 weight percent of the alumina added.
 12. Clear bright aluminum-containing dispersions containing at least about 6 weight percent aluminum dispersed in an oil-soluble dispersing agent selected from the group consisting of oil-soluble sulfonic acids in which the hydrocarbon portion has a molecular weight between about 350 and 1000 and hydrocarbyl carboxylic acids containing at least 8 carbon atoms, and an oleaginous carrier selected from the group consisting of mineral lubricating oils, synthetic lubricating oils, vegetable oils and animal oils, prepared by the process of claim
 1. 13. The dispersion of claim 12 wherein said aluminum is present in a form selected from salts of said sulfonic acids, salts of said hydrocarbyl carboxylic acids and alpha alumina monohydrate and in an amount equal to 8 to about 20 weight percent of the dispersion. 